Setup
Whenever you are altering your Github sites webpage, it is extremely useful to be able to preview the changes before you publish them. Also, there is a significant delay before changes to the repository are updated. The solution to these quandaries is to use Jekyll on your computer to locally build and host the webpage.
In order to do so, you will need to download Ruby and then to setup Jekyll. A quickstart guide is available here on Jekyll’s website. Note, however, that the website is already created by Github pages, so you may skip step three in their instructions and instead navigate to a local download of your Github repo.
Launching the Local Website
In a terminal in the directory of your local download of the repo, use the command:
bundle exec jekyll serve
to make your website available at http://localhost:4000.
In order to update the gems (Ruby program packages) you can use the command:
bundle update
Every now and then, you may receive a notice that one of the gems has an important update. By running this command, the gems will be updated and you can commit and push the new gemfile.lock to ensure the most recent version of the gems are being used.